大鼠中缝大核内P物质神经元的自调节突触

THE AUTOREGULATORY SYNAPSES OF SP-NEURONS IN THE NUCLEUS RAPHE MAGNUS OF RATS

用免疫电镜技术对大鼠延髓中缝大核的P物质能自调节突触进行了研究。结果表明:中缝大核内存在着P物质样免疫反应神经元胞体和神经纤维。阳性神经元以大型多极细胞为主。阳性神经纤维呈串珠状,除与免疫反应阴性结构形成突触联系外,尚与P物质样免疫反应的树突形成轴树型自调节突触。在自调节突触中,突触前、后成分均被免疫反应产物所标记。反应产物沉着于小清亮囊泡和树突小管周围、线粒体外膜及基质。突触前、后膜呈对称性。突触囊泡附于突触前膜。突触间隙宽约20 nm,内含电子致密物质。本文对自调节突触的普遍性、结构特点及机能意义进行了讨论。

Using immunoelectron microscopic technique the SPergic autoregulatory synapses in the nucleus raphe magnus were studied. The results showed that there were SPlike perikarya and nerve fibers. The positive perikarya mainly were large polypolar cells. The positive fibers appeared as beaded-like and formed axodendritic synapses with SP-positive dendrites besides synapses formed with SP-negative structures. In the autoregulatory synapses the pre- and postsynaptic element were both labeled with immunoreactive products which precipitated at the periphery of small clear synaptic vesicles and the dendritic tubes, on the outer membrane of mitochondria, and in the cytoplasmic matrix. The pre- and postsynaptic membrane were symmetrical, and the synaptic vesicles aggregated near the presynaptic membrane. The synaptic cleft was about 20 nm in width and contained electron dense materials. The generality, structural characteristics and functional significance of the autoregulatory sysnapses were discussed.